Modified carbon nanotubes/polyvinyl alcohol composite electrothermal films

Carbon nanomaterials are ideal materials for electrothermal applications because of their superior thermal conductivity, electrical conductivity, and mechanical properties. Electrothermal composites with excellent performance should have the characteristics of rapid temperature response, uniform heating temperature distribution, and good thermal stability after prolonged heating. However, for previously prepared electrothermal composites still have some shortcomings such as long temperature response time, uneven temperature distribution and poor thermal stability after long time heating. In this study, the composite electrothermal films with excellent performances were obtained by a layer-by-layer deposition approach, which were synthesized by pouring epigallocatechin gallate-functionalized multi-walled carbon nanotubes (E-MWCNTs) into a polytetrafluoroethylene mold and subsequently curing the polyvinyl alcohol (PVA) solution on the CNT layer. The electro-heating behavior of composite electrothermal film with different content and size was investigated by applying various voltages. They exhibit excellent electrothermal property, that is, a rapid temperature response, which can reach the steady-state temperature (TMAX) within 90 s. In addition, the maximum temperature can reach about 140 °C at 12 V. It was observed that the temperature of the composite electrothermal film has no significant change during the cycle tests of various voltages and 5 h aging time. According to the results of the experiment, the electrothermal properties of the composite electrothermal films are affected by the content of multi-walled carbon nanotubes (MWCNTs) and the applied voltage, which means that we can achieve accurate control of its properties by adjusting the content of MWCNTs and the applied voltage. Moreover, we have great expectations that these composite electrothermal films will have broad prospects for thermal management in wearable applications and electro-devices.